A study in the relationships between leptin, insulin, and body fat in Asian subjects

OBJECTIVE: To study the relationship of leptin concentrations with indices of obesity, fasting insulin, insulin resistance and lipid profiles (total cholesterol, low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)- cholesterol and triglyceride) in an Asian cohort. DESIGN: Cross sectional study. SUBJECTS: A total of 133 healthy volunteers were enrolled (64 female: age: 25-61 y, body mass index (BMI): 18.7-45.1 kg/m2 and 69 male: age: 25-61 y, BMI: 19.3-35.0 kg/m2). MEASUREMENTS: Weight, height, waist and hip circumferences, blood pressure, lean body mass (by bioelectric impedence analysis (BIA)), plasma leptin and lipid profiles were taken after a 10 h fast. RESULTS: Percentage of body fat measured by bioelectric impedance was the strongest determinant of plasma leptin (r = 0.844, P < 0.0001). Females had higher leptin concentrations than males for the same fat mass. In a multiple linear regression model, body fat percentage, (percentage body fat* gender), hip circumference and fasting insulin were significant determinants of leptin concentration (r = 0.882, P < 0.0001). CONCLUSION: Leptin concentration correlated closely with percentage body fat in Asian subjects. Hip circumference as a corollary for peripheral obesity, was better associated with leptin than waist circumference or waist-to-hip ratio (WHR). Distribution of fat in females tended to be peripheral and may partly explain the gender difference. Fasting insulin level and central obesity were correlated with HDL-cholesterol, triglyceride and blood pressure, while fasting leptin had little correlation with these metabolic parameters. Therefore, insulin resistance was a better guide to cardiovascular risk assessment than plasma leptin.     

Adiponectin, insulin resistance, and C-reactive protein in postpubertal Asian Indian adolescents

High-sensitivity C-reactive protein (hs-CRP) levels are closely associated with adiposity and predict coronary heart disease and type 2 diabetes mellitus. However, relationships of CRP to adiponectin and other markers of insulin resistance have been inadequately researched in children. We measured fasting serum levels of adiponectin, insulin, hs-CRP, and lipoproteins, and recorded the anthropometric profile and percentage of body fat (%BF; bioimpedance method) in 62 (36 normal weight, 26 overweight) healthy, urban, postpubertal Asian Indian males (aged 14 to 18 years). Serum levels of adiponectin were lower (P = not significant [NS]), whereas those of fasting insulin (P = .01) and hs-CRP (P = .02) were higher in overweight subjects. Adiponectin levels inversely correlated with body mass index (BMI; r = -0.26, P < .05), %BF (r = -0.24, P < .05), fasting insulin (r = -0.32, P < .05) and insulin resistance measured by the homeostasis model of assessment (HOMA-IR; r = -0.31, P < .05), but not with hs-CRP levels. Fasting insulin and hs-CRP levels correlated significantly with BMI, %BF, waist circumference (WC), waist-to-hip circumference ratio (W-HR), and triceps and subscapular skinfold thickness. The correlation of adiponectin with insulin sensitivity was independent of abdominal obesity, but became nonsignificant after controlling for BMI and %BF. Further, BMI was an independent predictor of adiponectin levels and the ratio of adiponectin and %BF was an independent predictor of fasting insulin levels. Although adiponectin levels did not correlate with hs-CRP levels, we observed dichotomous relationships of adiponectin and hs-CRP levels with generalized and abdominal obesity, respectively. We conclude that generalized obesity affects the adiponectin-insulin relationship in postpubertal Asian Indian males; however, the relationship of adiponectin with hs-CRP needs further evaluation.     

体重指数和腰围与代谢综合征发生风险的比较研究

目的 比较体重指数、腰围与代谢综合征发生风险的相关性.方法 554例人选者(男316例,女238例),按照体重指数和腰围被分为周围肥胖组192例、腹部肥胖组135例和混合肥胖组237例,7年后进行随访.结果 共随访到520例.周围肥胖组代谢综合征累积发生率26.3%(49/186),腹部肥胖组代谢综合征累积发生率41.7%(50/120),混合肥胖组代谢综合征累积发生率43.0%(92/214).腹部肥胖组和混和肥胖组代谢综合征累积发生率显著高于周围肥胖组(X2分别为7.825和12.082,均P＜0.01),且基线时舒张压、甘油三酯、空腹血糖、空腹胰岛素及稳态模型评估法胰岛素抵抗指数(HOMA-IR)也显著高于前者(均P＜0.05).以有或无代谢综合征分组后基线资料比较,代谢综合征组无论男女,腰围和腰臀比均高于非代谢综合征组(P＜0.01和P＜0.05),体重指数在两组无统计学差异,并且代谢综合征组空腹血糖、空腹胰岛素和HOMA-IR显著高于非代谢综合征组(均P＜0.05).Logistic回归显示,与代谢综合征发生风险相关的因素主要为腰围(P=0.021)、腰臀比(P=0.009)、HOMA-IR(P=0.004).结论 腹部脂肪堆积及胰岛素抵抗是代谢综合征发生的两个重要因素,腰围比体重指数与代谢综合征的发生风险关系更密切.     

脂肪细胞型脂肪酸结合蛋白与代谢综合征相关

代谢综合征(MS)组(n=121)的血清脂肪细胞型脂肪酸结合蛋白(A-FABP)水平较对照组(n=120)显著升高[(14.7±4.8 vs 6.8±3.0)μg/L,P<0.001].腹型肥胖MS患者的血清A-FABP水平较非腹型肥胖MS患者显著升高[(15.7±4.2 vs 12.6±5.1)μg/L,P<0.001].血清A-FABP水平与体重指数、腰围、腰臀比、空腹胰岛素、稳态模型评估的胰岛素抵抗指数、空腹血糖、甘油三酯、总胆同醇及平均动脉压等指标均呈正相关(r分别为0.603、0.534、0.411、0.424、0.401、0.370、0.460、0.208和0.522,均P<0.05),而与HDL-C旱显著负相关(r=-0.448,P<0.001).     

Abdominal obesity is associated with increased risk of acute coronary events in men.

AIMS: The purpose of the study was to investigate the associations of abdominal obesity and overall obesity with the risk of acute coronary events. METHODS AND RESULTS: Body mass index indicating overall obesity and waist-to-hip ratio and waist circumference indicating abdominal obesity were measured for 1346 Finnish men aged 42-60 years who had neither cardiovascular disease nor cancer at baseline. There were 123 acute coronary events during an average follow-up of 10.6 years. In Cox regression analyses adjusted for confounding factors, waist-to-hip ratio (P=0.009), waist circumference (P=0.010) and body mass index (P=0.013) as continuous variables were associated directly with the risk of coronary events. These associations were in part explained by blood pressure, diabetes, fasting serum insulin, serum lipids, plasma fibrinogen, and serum uric acid. Waist-to-hip ratio of > or =0.91 was associated with a nearly threefold risk of coronary events. Waist-to-hip ratio provided additional information beyond body mass index in predicting coronary heart disease, whereas body mass index did not add to the predictive value of waist-to-hip ratio. Abdominal obesity combined with smoking and poor cardiorespiratory fitness increased the risk of coronary events 5.5 and 5.1 times, respectively. CONCLUSIONS: Abdominal obesity is an independent risk factor for coronary heart disease in middle-aged men and even more important than overall obesity. Since the effect of abdominal obesity was strongest in smoking and unfit men, the strategy for lifestyle modification to prevent coronary heart disease should address these issues jointly.     

Circulating fatty acids, non-high density lipoprotein cholesterol, and insulin-infused fat oxidation acutely influence whole body insulin sensitivity in nondiabetic men

Circulating lipids and tissue lipid depots predict insulin sensitivity. Associations between fat oxidation and insulin sensitivity are variable. We examined whether circulating lipids and fat oxidation independently influence insulin sensitivity. We also examined interrelationships among circulating lipids, fat oxidation, and tissue lipid depots. Fifty-nine nondiabetic males (age, 45.4 +/- 2 yr; body mass index, 29.1 +/- 0.5 kg/m(2)) had fasting circulating nonesterified fatty acids (NEFAs) and lipids measured, euglycemic-hyperinsulinemic clamp for whole body insulin sensitivity [glucose infusion rate (GIR)], substrate oxidation, body composition (determined by dual energy x-ray absorptiometry), and skeletal muscle triglyceride (SMT) measurements. GIR inversely correlated with fasting NEFAs (r = -0.47; P = 0.0002), insulin-infused NEFAs (n = 38; r = -0.62; P < 0.0001), low-density lipoprotein cholesterol (r = -0.50; P < 0.0001), non-high-density lipoprotein cholesterol (r = -0.52; P < 0.0001), basal fat oxidation (r = -0.32; P = 0.03), insulin-infused fat oxidation (r = -0.40; P = 0.02), SMT (r = -0.28; P < 0.05), and central fat (percentage; r = -0.59; P < 0.0001). NEFA levels correlated with central fat, but not with total body fat or SMT. Multiple regression analysis showed non-high-density lipoprotein cholesterol, fasting NEFAs, insulin-infused fat oxidation, and central fat to independently predict GIR, accounting for approximately 60% of the variance. Circulating fatty acids, although closely correlated with central fat, independently predict insulin sensitivity. Insulin-infused fat oxidation independently predicts insulin sensitivity across a wide range of adiposity. Therefore, lipolytic regulation as well as amount of central fat are important in modulating insulin sensitivity.     

肿瘤坏死因子α和瘦素在肥胖及胰岛素抵抗中的作用

目的探讨血清TNFα及瘦素在肥胖和胰岛素抵抗中的作用。方法2型糖尿病病人84例,健康对照84例,分别测定血清TNFα、瘦素、血脂、空腹及餐后血糖、血清免疫反应性胰岛素(IRI)水平。并准确测量血压、身高、体重、腰臀围比(WHR)。结果肥胖者的TNFα及瘦素显著高于体重正常者,女性的瘦素血清水平高于男性2倍以上。相关分析结果显示,TNFα与HOMA胰岛素抵抗指数(HOMAIR)、WHR、空腹IRI呈正相关(r值分别为0.43、0.53、0.59,P<0.01),与高密度脂蛋白胆固醇呈负相关(r=-0.35,P<0.01)。瘦素与HOMAIR、空腹IRI呈正相关(r=0.31、0.29,P<0.05),男性的瘦素与WHR显著相关。TNFα与瘦素之间存在显著的正相关(r=0.29,P<0.05)。多元逐步回归分析表明,HOMAIR与TNFα的相关性最强,瘦素次之。血清TNFα水平与空腹血糖呈正相关。结论肥胖者的血清TNFα及瘦素水平与胰岛素抵抗密切相关,高水平的TNFα可能直接作用于脂肪组织调节瘦素的释放,而TNFα和瘦素协同作用诱导胰岛素的分泌,从而导致胰岛素抵抗。     

超重及肥胖人群血清网膜素-1水平的变化

目的 探讨在南京地区人群中超重及肥胖者血清网膜素-1水平的变化及其与体重指数、腰围、脂联素之间的相关性.方法 从2008年3月至7月全国糖尿病和代谢综合征患病率及变迁调查江苏分中心的南京地区调查人群中,选取42例超重及肥胖者和55名健康对照者,分别测定体重指数、腰围、空腹胰岛素、窄腹血糖、血脂、血清网膜素-1及脂联素的水平,计算腰臀比及胰岛素抵抗指数.采用SPSS 15.0软件进行统计学分析,血清网膜素-1和各指标问的相关性分析采用Pearson相关分析法.结果 健康对照者的血清网膜素-1浓度为(0.024±0.012)μg/L,脂联素浓度为(7.7±2.4)mg/L,超重及肥胖者的血清网膜素-1浓度为(0.016±0.007)μg/L,脂联素浓度为(6.4±3.1)mg/L.结果 显示超重及肥胖者的血清网膜素-1及脂联素水平明显低于健康对照者(P<0.05),且相关分析表明血清网膜素-1与体重指数(r=-0.321,P<0.05)、腰围(r=-0.312,P<0.05)、腰臀比(r=0.243,P<0.05)及甘油三脂(r=-0.220,P<0.05)之间旱显著负相关,与脂联索(r=0.232,P<0.05)呈明显正相关.结论 超莆及肥胖者的血清网膜素-1水平较健康对照者显著下降,且血清网膜素-1浓度变化与脂联素之间呈正相关,提示网膜素水平变化可能与肥胖、胰岛素抵抗和2型糖尿病密切相关.     

The associations between plasma adiponectin, ghrelin levels and cardiovascular risk factors

OBJECTIVE: Ghrelin is a recently discovered peptide, which is produced primarily in the stomach. This orexigenic peptide participates not only in the induction of mealtime hunger but also in long-term body weight regulation and energy homeostasis. Adiponectin is a protein secreted by adipocytes, and has been proposed to mediate obesity-related insulin resistance. Moreover, concentrations of adiponectin are reduced in individuals with obesity, insulin resistance and cardiovascular disease. However, human data are sparse about the direct relationship between adiponectin, ghrelin and cardiovascular risk factors including insulin resistance. DESIGN: Three hundred and thirty-eight elderly Korean women (mean age+/-s.d., 72.3+/-5.5 years) were included in the present study. METHODS: Plasma ghrelin and adiponectin levels were measured by RIA. Anthropometric measurements were taken and a 75 g oral glucose tolerance test performed. Fasting insulin and lipid profile were measured and insulin resistance was determined using the homeostasis model assessment insulin resistance index (HOMA-R) and the quantitative insulin sensitivity check index. RESULTS: Plasma adiponectin levels were negatively correlated with central obesity indices such as waist circumference (r=-0.27, P<0.001) and waist-to-hip ratio (WHR) (r=-0.32, P<0.001), and with insulin resistance indices such as fasting insulin (r=-0.17, P=0.004) and HOMA-R (r=-0.13, P=0.035). Plasma ghrelin levels were negatively correlated with WHR (r=-0.12, P=0.03), but plasma adiponectin and ghrelin levels were not correlated (r=0.03, P=0.66). Multiple regression analysis showed that adiponectin was associated with WHR, fasting insulin and fasting glucose levels. When ghrelin was used as a dependent variable, only WHR remained in the final fitted model. CONCLUSION: Fasting plasma adiponectin and ghrelin levels were found to be associated with central obesity or insulin resistance. However, plasma adiponectin and ghrelin concentrations were not associated with each other in elderly Korean women.     

Physiological relationships of uncoupling protein-2 gene expression in human adipose tissue in vivo

The physiological significance of changes in uncoupling protein-2 (UCP-2) gene expression is controversial. In this study we investigated the biochemical and functional correlates of UCP-2 gene expression in sc abdominal adipose tissue in humans in vivo. UCP-2 messenger ribonucleic acid expression was quantified by nuclease protection in adipose tissue from lean and obese humans in both the fasting and postprandial states. Plasma fatty acids, insulin, and leptin were all determined in paired samples from the superficial epigastric vein and radial artery, and local production rates were calculated from 133Xe washout. In the fasting state UCP-2 expression correlated inversely with body mass index (r = -0.45; P = 0.026), percent body fat (r = -0.41; P = 0.05), plasma insulin (r = -0.47; P = 0.02), epigastric venous fatty acids (r = -0.45; P = 0.04), and leptin (r = -0.50; P = 0.018). UCP-2 expression remained inversely related with plasma leptin after controlling for percent body (r = -0.45; P = 0.038). At 2 or 4 h postprandially, there were no significant relationships between UCP-2 expression and biochemical parameters. In conclusion, 1) UCP-2 messenger ribonucleic acid expression in sc adipose tissue is inversely related to adiposity and independently linked to local plasma leptin levels; and 2) UCP-2 expression is not acutely regulated by food intake, insulin, or fatty acids. Reduced UCP-2 expression may be a maladaptive response to sustained energy surplus and could contribute to the pathogenesis and maintenance of obesity.     

Relationship of dietary fat and serum cholesterol ester and phospholipid fatty acids to markers of insulin resistance in men and women with a range of glucose tolerance

High-fat diets are associated with insulin resistance, however, this effect may vary depending on the type of fat consumed. The purpose of this study was to determine the relationship between intakes of specific dietary fatty acids (assessed by 3-day diet records and fatty acid composition of serum cholesterol esters [CEs] and phospholipids [PLs]) and glucose and insulin concentrations during an oral glucose tolerance test (OGTT). Nineteen men and 19 women completed the study. Nine subjects had type 2 diabetes or impaired glucose tolerance. Fasting insulin correlated with reported intakes of total fat (r = .50, P < .01), monounsaturated fat (r = .44, P < .01), and saturated fat (r = .49, P < .01), but not with trans fatty acid intake (r = .11, not significant [NS]). Fasting glucose also correlated with total (r = .39, P < .05) and monounsaturated fat intakes (r = .37, P < .05). In multivariate analysis, both total and saturated fat intake were strong single predictors of fasting insulin (R2 approximately .25), and a model combining dietary and anthropometric measures accounted for 47% of the variance in fasting insulin. Significant relationships were observed between fasting insulin and the serum CE enrichments of myristic (C14:0), palmitoleic (C16:1), and dihomo-gamma-linolenic (C20:3n-6) acids. In multivariate analysis, a model containing CE 14:0 and percent body fat explained 45% of the variance in fasting insulin, and C14:0 and age explained 30% of the variance in fasting glucose. PL C20:3n-6 explained 30% of the variance in fasting insulin, and a model including PL C18:1n-11 cis, C20:3n-6, age and body fat had an R2 of .58. In conclusion, self-reported intake of saturated and monounsaturated fats, but not trans fatty acids, are associated with markers of insulin resistance. Furthermore, enhancement of dihomo-gamma-linolenic and myristic acids in serum CE and PL, presumably markers for dietary intake, predicted insulin resistance.     

Subclinical inflammation and soleus muscle intramyocellular lipids in healthy Asian Indian males

OBJECTIVES: The relationship between C-reactive protein (CRP), a marker of subclinical inflammation, and intramyocellular lipid (IMCL) content, a novel correlate of insulin resistance, has not previously been investigated. METHOD AND DESIGN: We estimated IMCL content in soleus muscle in 30 healthy Asian Indian males using proton magnetic resonance spectroscopy ((1)H MRS), and correlated it with body mass index (BMI), measures of abdominal obesity, percentage of body fat (%BF), serum lipoproteins, fasting and post-oral glucose load serum insulin levels and other surrogate markers of insulin resistance. RESULTS: Soleus muscle IMCL content was significantly correlated with age (rho=0.64, P<0.001), BMI (rho=0.41, P<0.05), %BF (rho=.53, P<= 0.01), waist circumference (rho=0.45, P<0.05) and waist-to-hip circumference ratio (rho=0.58, P<0.01) but did not correlate significantly with insulin resistance measured by the homeostasis model assessment (HOMA-IR) or CRP levels. CRP levels did not correlate with the HOMA-IR value. CONCLUSIONS: Soleus muscle IMCL content correlated significantly with measures of generalized and abdominal obesity but not with insulin sensitivity or CRP levels in healthy Asian Indian males. Studies are needed in other ethnic groups to corroborate these data.     

Multiple indexes of lipid availability are independently related to whole body insulin action in healthy humans

An increase in muscle lipid content has been postulated to relate closely to the evolution of insulin resistance. We aimed to test whether the multiple indexes of lipid supply within man [namely, circulating triglycerides, skeletal muscle triglycerides (SMT), total and central fat mass, and circulating leptin] were independent predictors of insulin resistance, or whether triglycerides from different sources are additive in their influence on whole body insulin sensitivity. Whole body insulin sensitivity, body composition, and SMT content were determined in 49 sedentary, nondiabetic males (age, 20-74 yr; body mass index, 20-38 kg/m(2)). Insulin sensitivity was inversely associated with central abdominal fat (r(2) = 0.38; P < 0.0001), total body fat (r(2) = 0.21; P = 0.0003), SMT content (r(2) = 0.16; P = 0.005), and fasting triglycerides (r(2) = 0.24; P = 0.0003), nonesterified free fatty acid (r(2) = 0.19; P = 0.002), and leptin (r(2) = 0.35; P < 0.0001) levels. However, only central abdominal fat was significantly related to SMT content (r(2) = 0.10; P = 0.03). SMT content, circulating triglycerides, and measurements of total or central adiposity were independent predictors of whole body insulin sensitivity.     

Effect of obesity on circulating intermediary metabolite concentrations in the absence of impaired glucose tolerance.

The published literature on the influence of obesity on intermediary metabolite concentrations does not adequately address the potential confounding effects of the increased prevalence of impaired glucose tolerance in obese subjects. In order to remove this, we studied 109 subjects with proven normal glucose tolerance ranging from underweight to grossly obese (range 15.3-80.9 body mass index). All had blood intermediary metabolites, plasma insulin and C-peptide measured after an overnight fast. Thirty-six (18 from each end of the range of body mass index) received a 3-hour oral glucose tolerance test for metabolites and insulin. Fasting plasma insulin was highly significantly associated with body mass index (r = 0.72; P less than 0.001). Concentrations of lipid intermediaries were better associated with body mass index than with fasting plasma insulin: non-esterified fatty acids (r = 0.36; P less than 0.001), glycerol (r = 0.47; P less than 0.001) and ketone bodies (r = 0.45; P less than 0.001). Fasting concentrations of carbohydrate intermediaries were, however, better correlated with fasting plasma insulin: lactate (r = 0.29; P less than 0.01), pyruvate (r = 0.24; P less than 0.01) and alanine (r = 0.36; P less than 0.001). Glucose concentrations were associated with both to a similar degree (r = 0.33, r = 0.32, respectively; P less than 0.001). After oral glucose, exaggerated rises in plasma insulin and blood glucose were observed in obese subjects but a lesser rise was seen for lactate. Non-esterified fatty acids and ketones, although having higher fasting concentrations in obese subjects, fell to similar concentrations in the two groups after glucose whereas blood glycerol did not fall so far in the obese subjects. The results suggest, even if those subjects with impaired glucose tolerance are excluded, insensitivity to insulin in several aspects of intermediary metabolism in obesity the degree of which may vary in different metabolic pathways or tissues.     

Association between birth weight and insulin sensitivity in healthy young men in Korea: role of visceral adiposity

Recent studies have demonstrated decreased insulin sensitivity in individuals with low birth weight. This study was performed to examine whether abdominal obesity is a link between insulin resistance and low birth weight. We studied the relationships between birth weight and insulin secretion, insulin sensitivity, and various anthropometric indices including visceral fat area in 22 healthy young Korean adults. Birth weight correlated significantly with diastolic blood pressure (r=-0.47, P<0.05) and insulin sensitivity index (S(I)) measured by a frequently sampled intravenous glucose tolerance test (FSIGT) (r=0.54, P<0.05), but not with insulin secretory indices such as acute insulin responses during FSIGT (r=-0.35, NS) or hyperglycemic clamp (r=0.17, NS) and submaximum insulin response during hyperglycemic clamp (r=0.10, NS). S(I) correlated significantly with abdominal obesity measurements such as waist circumference (r=-0.48, P<0.05), waist-to-hip ratio (r=-0.53, P<0.05) and visceral fat area (r=-0.58, P<0.01). However, we could not find significant correlation between birth weight and any of the abdominal obesity measurements (r=-0.35 for waist-to-hip ratio, r=-0.22 for visceral fat area, and r=-0.24 for visceral-to-subcutaneous fat ratio; NS for all). The present data confirm that low birth weight is associated with insulin resistance in adult life. However, our data suggest that the association between low birth weight and insulin resistance is not mediated by abdominal obesity.     

新诊断2型糖尿病患者血清铁蛋白与糖、脂代谢及胰岛功能的关系

目的 比较不同血清铁蛋白(SF)水平的新诊断2型糖尿病(T2DM)患者糖、脂代谢及胰岛功能,分析其与SF的关系.方法 以新诊断T2DM患者115例为观察对象,按SF浓度分为高SF组40例(SF≥274.66 μg/L)与正常SF组75例(21.80 μg/L≤SF< 274.66 μg/L).测量两组患者的身高、体重、腰围、臀围,检测空腹血糖、餐后2h血糖(2 hPG)、HbA1c、空腹胰岛素(FINS)、总胆固醇、甘油三酯、高密度脂蛋白-胆固醇(HDL-C)、低密度脂蛋白-胆固醇(LDL-C),计算体重指数、腰臀比、稳态模型评估-胰岛素抵抗指数(HOMA-IR)、稳态模型评估-胰岛β细胞功能指数(HOMA-β)、定量胰岛素敏感性指数(QUICKI)和处置指数,并进行Spearman相关性及多元线性回归分析.结果 高SF组体重指数、FINS、甘油三酯、HOMA-IR高于正常SF组(t=2.470、2.631、2.316、2.879,P均<0.05),HDL-C、QUICKI低于正常SF组(t=-2.030、-2.623,P均<0.05);SF水平与体重指数、腰臀比、空腹血糖、2 hPG、HOMA-IR、甘油三酯均呈正相关(r=0.191 ～0.303,P均<0.05),与HDL-C、QUICKI、处置指数呈负相关(r=-0.221、-0.261、-0.293,P均<0.05);多元线性回归分析显示体重指数、处置指数和甘油三酯是SF的独立相关因素(β=0.041、-0.443、0.270,P均<0.05).结论 高SF水平的新诊断T2DM患者其糖、脂代谢紊乱及胰岛素抵抗程度较正常SF的T2DM患者更严重,SF可能通过增加胰岛素抵抗,促进T2DM的发生和发展.     

超重和肥胖者血管内皮功能障碍的相关因素分析

目的探讨超重和肥胖者血管内皮功能障碍的相关因素.方法367例单纯超重和肥胖者,其中血管内皮功能正常组122例,血管内皮功能异常组245例.通过反应性充血时肱动脉内径变化,评估血管内皮功能,并对体脂含量和分布、血压、血糖、胰岛素、血脂、肌酐、尿酸和胰岛素抵抗指数(HOMA-IR)等指标进行测定,应用相关分析和多元线性回归方程分析血管内皮功能与上述指标的相关性.结果血管内皮功能异常组的腰围、腰臀比、餐后血糖、空腹胰岛素、餐后胰岛素和HOMA-IR均显著高于血管内皮功能正常组(P＜0.05～0.01).进一步分析表明内皮依赖性血管舒张功能与体重指数、腰围、腰臀比、空腹胰岛素及HOMA-IR呈负相关,其中腰臀比和空腹胰岛素是内皮依赖性血管舒张功能损伤的重要相关因素.结论单纯超重或肥胖人群中,向心性肥胖及空腹胰岛素水平升高是影响血管内皮功能的重要因素.     

Computed tomography scans of intra-abdominal fat, anthropometric measurements, and 3 nonobese metabolic risk factors

The present cross-sectional study of 46 adult Danish white men and women aimed to evaluate association between intra-abdominal obesity, 4 anthropometric measurements of obesity, and combinations of 3 nonobese metabolic risk factors: systolic blood pressure of 130 mm Hg or higher, serum triglyceride concentration of more than 1.7 mmol/L, and fasting capillary blood glucose concentration of 5.6 mmol/L or more. For 80% of the subjects, intra-abdominal fat on a computed tomography scan of the abdomen using a cutoff limit of more than 144 cm(2) gave a correct classification of combinations of at least 2 of the 3 metabolic risk factors. Body mass index and waist circumference were better markers of intra-abdominal obesity than waist-to-hip ratio in receiver operating characteristic analyses (P = .0035). Body mass index of more than 26 kg/m(2) and waist circumference of more than 0.92 m classified 76% and 74% of the subjects correctly regarding combinations of the 3 nonobese metabolic risk factors. Intra-abdominal obesity was significantly stronger associated with the combinations than a raised waist-to-hip ratio (P = .016). Both body mass index and waist circumference may be used as markers of intra-abdominal obesity, whereas waist-to-hip ratio was significantly inferior. Correspondingly, both body mass index and waist circumference were better than waist-to-hip ratio to indicate combinations of the 3 nonobese metabolic risk factors.     

Nutrition and serum cholesterol levels among elderly men and women (Dutch Nutrition Surveillance System).

Associations of serum cholesterol with relevant dietary intake variables (assessed with the dietary history method) and body mass index were investigated in elderly men (n = 199) and women (n = 180) 65-79 years old. All subjects were apparently healthy, nondiabetic, and not on a dietary regimen. The associations were studied separately for men and women using linear regression analysis and all possible subsets regression analysis. Among men, body mass index (kg/m2) and intake of monounsaturated fat and of alcohol were positively and consistently associated with serum total cholesterol. Among women, intake of alcohol and of saturated fat were positively associated, and intake of polysaccharides was inversely associated with serum total cholesterol. The intake of monounsaturated fatty acids was highly (r greater than .60) positively correlated with the intake of total fat and saturated fatty acids, and inversely with carbohydrates. HDL-cholesterol was positively associated with alcohol intake (significant for men only), and inversely with body mass index (women). The results indicate that the effect of dietary factors on serum cholesterol levels is probably not age-limited. Elderly people may potentially benefit from weight reduction or control, moderate alcohol consumption, and avoidance of too much dietary fat. These suggestions are in fair accordance with general population-based guidelines for a healthy diet. However, as our study was cross-sectional, causation as well as the public health impact remains to be proven.     

不同糖耐量人群血清25(OH)D3水平及与胰岛β细胞功能的关系

目的 比较不同糖耐量人群血清25(OH)D3水平,分析其与胰岛β细胞功能的关系.方法 共纳入131例受试者,包括新诊断2型糖尿病患者(T2DM组)50例,糖调节受损者(IGR组)45名和糖耐量正常者(NGT组)36名.收集临床资料并检测相关生化指标,采用酶联免疫吸附法测定空腹血清25(OH)D3水平.结果 NGT组、IGR组和T2DM组血清25(OH)D3水平依次下降(F=25.984,P＜0.05).血清25 (OH)D3与体重指数、腰围、臀围、腰臀比、空腹血糖、口服葡萄糖耐量试验2 h血糖(2 hPG)呈负相关(r=-0.600 ～-0.175,P均＜0.05),与空腹胰岛素(FINS)、胰岛素曲线下面积、稳态模型评估-胰岛β细胞功能指数、早相胰岛素分泌指数(△INS30/△G30)呈直线正相关(r=0.296～0.693,P均＜0.05).多元逐步回归分析显示,2hPG、△INS30/△G30是血清25(OH)D3水平的独立相关因素(β=0.204,-0.178,P均＜0.05).结论 IGR者与T2DM患者25(OH)D3水平降低.血清25(OH)D3与胰岛素分泌功能呈正相关,与肥胖、血糖水平呈负相关.